In 1820 Rufus Porter, a Yankee inventor, and later the original founder of the Scientific American, patented an air ship of very promising appearance for that early day. Its hull was a long, finely tapering symmetrical spindle, suspending a car of similar shape by means of cords, which were vertical at its middle but more and more slanting toward its ends. Midway between the hull and car was a large screw propeller actuated by a steam engine in the car. A model of this dirigible exhibited in Boston and New York, some years later, is reported to have carried its own power, at fair speed, and to have obeyed its helm satisfactorily.